Recently purchased a 2012 Sunseeker 2450 used. The AC fan runs when the furnace is on. Is that normal ? Also was trying to install a winterizing siphon antifreeze kit and theres not enough room next to the water pump for the fitting. Anyone have a solution to this ?

First guess on AC us that the T-stat is set to fan on hi or low and not auto

That is correct. Push the on-off button on thermostat to "fan". Then use + or - to change display to "au" (auto) instead of hi or lo. Return to furnace and furnace fan will run as needed but a/c fan will not.

That is correct. Push the on-off button on thermostat to "fan". Then use + or - to change display to "au" (auto) instead of hi or lo. Return to furnace and furnace fan will run as needed but a/c fan will not.

Recently purchased a 2012 Sunseeker 2450 used. The AC fan runs when the furnace is on. Is that normal ? Also was trying to install a winterizing siphon antifreeze kit and theres not enough room next to the water pump for the fitting. Anyone have a solution to this ?

Anywhere in the suction line enroute to the fresh water tank, that's accessible. Must valve off tank and open to AF to accomplish the task. Best way is 3 way valve. One twist accomplishes both. The AC fan operating is good for circ of the warm air, thats the reason for it.

Recently purchased a 2012 Sunseeker 2450 used. The AC fan runs when the furnace is on. Is that normal ? Also was trying to install a winterizing siphon antifreeze kit and theres not enough room next to the water pump for the fitting. Anyone have a solution to this ?

Had a similar problem on my 3120. Inlet to the pump was right at an elbow. Installed the three way valve with the pump suction to the leg of the 3 way valve "T" and the anti freeze hose connection at the bottom. Had to file off the valve stop so it now rotates 180 degrees instead of just 90 to swap from normal to antifreeze bypass. Just a little pipe fitting work to plumb it up, new straight fitting to replace the elbow and shortening of the flex hose to get things to line up. If you like I may be able to get a photo.